chrono-, chron-

(Greek: time, times; sequence of times)

pseudochronology (s) (noun), pseudochronologies (pl)
Inaccuracy in placing incorrect times for events or occurrences: James had a very bad memory and was known to be an expert in pseudochronology by getting the ages of his children all mixed up, and thinking that his wife was much younger than she really was!
psychochronometry (s) (noun) (no pl)
The research of mental processes in relation to their timing and duration: In his medical studies Tony thought that he would take a course in psychochronometry in order to learn more about the human brain and its cognitive performances.
seismochronograph (s) (noun), seismochronographs (pl)
A chronograph (an instrument that records time with great accuracy) for determining the time at which an earthquake shock happens: Earthquakes do take place in Southern California where scientists use seismochronographs to track the precise time of earthquakes and the shocks.
sphygmochronograph (s) (noun), sphygmochronographs (pl)
A modified sphygmograph that represents graphically the time relations between the beat of the heart and the pulse; a recording of the character of the pulse as well as its rapidity: Jane learned that a sphygmochronograph was a device that recorded the number of pulsations per minute.
sphygmochronography (s) (noun), sphygmochronographies (pl)
The registration of the time intervals of the pulse waves: Sphygmochronography concerns the documentation of the pulse by automatic means.
synchromesh (s) (noun), synchromeshes (pl)
An automatic gear shift system in which the gears are synchronized at the same speeds before engaging to effect a smooth change: When Susan was thinking about buying a new car, she definitely wanted one with synchromesh so that the transmission would perform smoothly.
synchronal (adjective), more synchronal, most synchronal
An outdated term regarding things occurring at the same time or rate, synchronous: All the cuckoo clocks in the shop were synchronal and all the little birds in the clocks chirped loudly together at 12 noon!
synchronia (s) (noun) (no pl)
The commencement, growth, or the activity of organs or tissues in a body at the normal time: Dr. Small, the pediatrician, checked the synchronia of Jane's baby girl at regular intervals to make sure that she was in good health.
synchronic (adjective) (not comparable)
1. Concerning something happening at the same time: Virginia's grandfather clock and the old school clock were very synchronic in that both of them could be heard at the full hours at the same time!
2. In medicine, referring to the study of the natural history of a disease by its state and distribution in a population at one time: The inferences about the longitudinal course from such a synchronic study are warranted only under special conditions, notably that the longitudinal course of the disease is itself unchanging and that subjects in the sample are a representative sample of the survivors.

synchronicity (s) (noun), synchronicities (pl)
The phenomenon of events which coincide in time and appear meaningfully related but have no discoverable causal connection: The synchronicity of Grace and Mary giving birth to their baby gils almost at the same time, and both naming their baby girls Jenifer with one "n", was quite remarkable!
synchronism, synchrony (s) (noun), synchronisms; synchronies (pl)
1. The quality of being synchronous; the occurrence of two or more events at the same time: The synchronism of the two concerts in the city was not expected and meant that they would take place simultaneously, meaning that it was difficult for people to choose which one to go to!
2. Arrangement or treatment of synchronous events, etc. together or in conjunction: Mr. Straight was responsible for the synchronism of the city's historical events and important persons by putting them into tabular lists to show similarities in the occurrences.
3. Representation of events of different times together, e.g. in the same picture: As an example of synchronism at the museum, Mary saw a big work of art showing various incidents and occurrences that happened at different times in history.
synchronist (s) (noun), synchronists (pl)
One who lives at the same time with another; a contemporary: Monika's mother is said to have been a synchronist who lived at exactly the same time as the Queen Elisabeth of England.
synchronistic (adjective) (not comparable)
1. Descriptive of something arranged according to correspondence in time; synchronistical: Tom thought that the synchronistic occurrences and chance meetings happened more often than supposed.
2. Relating to something belonging to synchronism; relating to or exhibiting the concurrence of events in time: Synchronistic incidences can be simultaneous events, or taking place at the same time.
synchronization (s) (noun), synchronizations (pl)
The relation that is present when things happen at the same time; synchronism: The leader said that the synchronization of the hikers watches was of utmost importance.

With precise synchronisation the boys jumped into the swimming pool.

synchronize (verb), synchronizes; synchronized; synchronizing
1. To occur at the same time; to coincide in point of time; to be contemporary or simultaneous: The couple tried to synchronize their work schedule so that they could go on vacation together.
2. To cause to be, or represent as, synchronous; to assign the same date to; to bring together events, etc. belonging to the same time: Mr. and Mrs. Smith got out their date books in order to synchronize the important events they had to organize.
3. To occur at the same successive instants of time; to keep time with; to go on at the same rate and exactly together; to have coincident periods as two sets of movements or vibrations: The conductor of the chamber orchestra wanted all the strings to synchronize their bowing so as to keep the exact tempo of the piece.
4. To cause to go at the same rate, specifically to cause (a timepiece) to indicate the same time as another: The two girls synchronized their watches before going rock climbing in the Alps.
5. In technical senses: to cause to coincide in time; to operate simultaneously: The coordinator tried to synchronize the activities at school, but it didn't work out, and everything took much longer than expected.