I. prefix
Etymology: Middle English, from Latin; akin to Old English twi- — more at twi-
1.
a. : two
bi muscular
bi cycle
bi racial
b. : lasting two : coming or occurring every two
bi ennial
bi monthly
bi weekly
c. : into two parts
bi sect
2.
a. : twice : doubly : on both sides
bi conic
bi convex
bi serrate
b. : coming or occurring two times
bi diurnal
bi quarterly
bi weekly
— often disapproved in this sense because of the likelihood of confusion with sense 1b; compare semi-
3. anatomy : between, involving, or affecting two (specified) symmetrical parts
bi gonial
bi -iliac
4. chemistry
a. : containing one (specified) constituent in double the proportion of the other constituent or in double the ordinary proportion — especially in names of acid salts formed with twice as much acid as is required for a normal salt
bi urate
b. : di- 2 — especially in names of organic compounds to denote the doubling of a radical or molecule
bi tolyl
bi phenol
II. combining form
or bio-
Etymology: Greek, from bios mode of life — more at quick
1. : life
bio blast
: living organisms or tissue
bi opsy
bio dynamics
2. : biology : biological
bio psychology
III. combining form
or bio-
: biographical
bio pic
: biographical and
bio critical