Webster's Revised Unabridged Dictionary · 1913

Infix

Infix , transitive verb

[Latin infixus, p. p of infigere to infix; pref. in- in + figere to fix: compare French infixer. See Fix.]

1.
To set; to fasten or fix by piercing or thrusting in; as, to infix a sting, spear, or dart. — Shakespeare
The fatal dart a ready passage found, And deep within her heart infixed the wound. — Dryden
2.
To implant or fix; to instill; to inculcate, as principles, thoughts, or instructions; as, to infix good principles in the mind, or ideas in the memory.

Infix , noun

1.
Something infixed. [Rare] — Welsford
2.
(Grammar) An element that is inserted into the body of an elemt which it threby modifies, as a letter within a word.