Meaning of I- in English

I-

I. combining form

Etymology: i nactive

: inactive (sense c)

i -inositol

— usually joined to second element with a hyphen

II. combining form

Etymology: by shortening

: is- 2b

i -butyl

— usually joined to second element with a hyphen

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.