in-2 repr. L. in-, cogn. and synon. with Gr. a(n)- A-4 and Gmc. *un- UN-1, as in fēlix happy/infēlix unhappy, nocēns hurtful/innocēns innocent; in earlier L. the pref. retained its n, but later this was assim. to l, m, r (see IL-2, IM-2, IR-2); before g it was reduced to i-, as in ignōrāre ignore. In a few OF. words this in- became en-, e.g. L. inimīcus, OF. enemi enemy, L. invidia, OF. envie envy; but most F. words containing this pref. are of learned orig. and retain in- (il-, etc.).

in-1 repr. L. in- (cf. prec.), used in combination mainly with vbs. and their derivs. with the senses ‘in, into, within, on, towards, against’; in earlier L. the prefix retained its n, but later this was assim. to l, m, r (see IL-1, IM-1, IR-1). In OF. in-, im- became en, em- (see EN-1, EM-1) in inherited words, but in learned words in-, im- were regularly retained.

in-¹ • prefix 1. (added to adjectives) not: inanimate intolerant.2. (added to nouns) without; lacking: inadvertence inappreciation.

in- (im-) prefix denoting
1. not.

2. in; within; into.