-al; -ial, -eal

(Latin: suffix; pertaining to, like, of the kind of, relating to, characterized by, belonging to; action of, process of)

asterial (adjective), more asterial, most asterial
Pertaining to stars: A starfish has a very asterial shape, for example.
atlantoaxial (adjective) (not comparable)
Referring to the atlas and the axis; denoting the joint between the first two cervical vertebrae: The first and second cervical vertebrae that meet at the joint is called the atlantoaxial joint.

The uppermost cervical vertebra (the atlas) rotates around the odontoid process of the second cervical vertebra (the axis). The joint between the axis and atlas is a pivot type of joint that allows the head to turn.

atonal (adjective), more atonal, most atonal
Concerning music that is played without harmony; lacking harmony; unharmonious: During the recital, James couldn't stand the atonal pieces that the pianist played, so he left the room.
atrial (adjective) (not comparable)
1. Relating to or belonging to the central area in a building that is open to the sky: The atrial part of a big shopping center is quite large and extends through many floors to the top of the structure and often has a skylight!
2. Pertaining to an atrium of the heart: An atrial chamber is connected to other chambers or passageways, especially one of the two upper chambers of the heart.
aural (adjective), more aural, most aural
1. Characterized by, or pertaining, to the ear or hearing: Nigel's mother had excellent aural abilities and could even hear every word that was whispered in the room next door!
2. Regarding an aura: Jenny noticed aural symptoms that always preceded her migraine headaches.
auspicial (adjective), more auspicial, most auspicial
Of or pertaining to a favorable sign or indicating that a future success is probable for an activity: James found that it was an auspicial decision to apply for a new job after his previous employment was terminated because the company he worked for was decreasing the number of workers they had for economic reasons.
axial (adjective), more axial, most axial
Relating to or operating along an axis: The planet Earth moves once a day in an an axial rotation.
axial-flow (adjective) (not comparable)
Referring to any liquid flowing parallel to an axis; axisymmetric flow: In turbomachinery the axial-flow turbine always moves parallel to the length of the rotating shaft,.
bacterial (adjective) (not comparable)
In microbiology, pertaining to bacteria: Dr. Big told Alice that she had a bacterial infection due to microorganisms which were causing her to feel so ill, and that it could be treated
balneal (noun), more balneal, most balneal
Rare, of or pertaining to baths or to bathing: The spa that Jane went to had physical and balneal therapy included in the price.
beneficial (adjective), more beneficial, most beneficial
Descriptive of that which brings about a positive result, is favorable, and good: Drinking lots of fresh water is a beneficial action which supports good health.
biaxial (adjective) (not comparable)
Referring to something that possess two axes: Some crystals are biaxial in that they have two optical axes in which a birefringence does not take place.
biennial (adjective) (not comparable)
Pertaining to something that happens every two years: The family got together on a biannual basis to celebrate birthdays.

A biennial plant lives for two years and produces flowers and fruit in the second year.

Note: "biannual" means "twice a year"; which is, within the same year.

bilabial (adjective) (not comparable)
Concerning a sound in speech that is articulated using both lips: Bilateral movement of the lips is in action when verbalising the the "p" in the words "past" and "present".
bilateral (adjective), more bilateral, most bilateral
1. In politics, involving or carried out by two groups: Bilateral affairs of states can especially pertain to the political representatives of two countries.
2. Relating to or affecting both of two sides: Bilateral talks were organised between Canada and China.
3. Relating to the right and left side of a body structure: At the ottorhynolaynologist's, the hearing test results showed that Mary had a bilateral hearing impairment.