bi-, bin-, bino-, bis-

(Latin: two, twice, double, twofold; a number; it normally functions as a prefix)

This bi- is used before s, c, or a vowel. Don't confuse this bi- with another one which means "life".

All words except biennial referring to periods of time and prefixed by bi- are potentially ambiguous. Since bi- can be taken to mean either "twice each" or "every two", a word like "biweekly" can be understood as "twice each week" or "every two weeks".


To bisect is to cut into two parts.

bisect, dissect
bisect (BIGH sekt", bigh SEKT) (verb)
To cut or to divide into two parts; especially, two equal parts: The lines on the map served to bisect the property into two sections.
dissect (di SEKT, digh SEKT, DIGH sekt") (verb)
To separate into sections for close scientific analysis or interpretation: The students in the biology class each had a frog to dissect as their class project.

The diagram showing us how to dissect the specimen directed us first to bisect it from right to left.

bisected, dissected
bisected (BIGH sekt'd) (verb)
1. Having cut or divided something into two parts: The city was bisected by the highway.
2. Having split or forked: The driver noticed that the highway was bisected by a median strip which consisted of many beautiful trees.
dissected (DIGH sekt'd) (verb)
1. Having cut apart or separated (tissue), especially for anatomical studies: As part of the anatomy class, the students dissected a large worm which smelled awful.
2. To have examined, analyzed, or criticized in minute details: They dissected the company plan afterward to learn why it failed.

The panel dissected each point of Oscar's argument.

Jorge and Annie got lost when they discovered that, when the highway had bisected, they took the wrong turn.

There was a great deal of discussion while the driver and the tour guide dissected the problem before deciding what to do.

bisensory (adjective) (not comparable)
Relating to or affecting two perceptions: The rapid changes in the weather had a bisensory impact on Molly because she could feel the rain on her head and hear the wind blowing among the trees at the same time. 
Having two bristles.
bisociation (s), bisociations (pl)
An association of an object with two or more ideas.

Arthur Koestler wrote that any creative act is a bisociation (not a mere association) of two (or more) apparently incompatible frames of thought.

"The originality of genius, in art as in science, consists of a shift of attention to aspects of reality previously ignored, discovering hidden connections, seeing familiar objects or events in a new light."

—Arthur Koestler (author of fiction, non-fiction, history, autobiography, politics, philosophy,
psychology, parapsychology, and science) in his book, The Act of Creation;
Penguin Books; New York; 1964.
bisulcate, bisulcous
1. With, or having, two grooves or furrows.
2. Cloven; said of a foot or hoof; cloven-hoofed.