1766, from Modern Latin tactica, from Greek taktikē (tekhnē) "(art of) arrangement," from fem. of taktikos "pertaining to arrangement" (see tactics). Earlier it meant "a tactician" (1630s), and was in use as an adjective meaning "tactical" (c. 1600).
-ian
variant of suffix -an (q.v.), with connective -i-. From Latin -ianus, in which the -i- originally was from the stem of the word being attached but later came to be felt as connective. In Middle English frequently it was -ien, via French.