next after the first in order, place, time, etc.

belonging or pertaining to a second order, division, stage, period, rank, grade, etc.

derived or derivative; not primary or original

secondary sources of historical research.

of minor or lesser importance; subordinate; auxiliary.

of or pertaining to secondary schools.

Chemistry .

involving or obtained by the replacement of two atoms or groups.

noting or containing a carbon atom united to two other carbon atoms in a chain or ring molecule.

Electricity . noting or pertaining to the current induced by a primary winding or to the winding in which the current is induced in an induction coil, transformer, or the like.

Geology . noting or pertaining to a mineral produced from another mineral by decay, alteration, or the like.

Grammar .

derived.

derived from a word that is itself a derived word

a secondary derivative.

having reference to past time; noting or pertaining to a past tense

the Latin, Greek, or Sanskrit secondary tenses. Compare primary def. 13

Ornithology . pertaining to any of a set of flight feathers on the second segment of a bird's wing.

Linguistics . of, pertaining to, or characteristic of a secondary accent

secondary stress.

a person or thing that is secondary.

a subordinate, assistant, deputy, or agent.

Electricity . a winding in a transformer or the like in which a current is induced by a primary winding.

Ornithology . a secondary feather.

Football . the defensive unit that lines up behind the linemen.

Linguistics . secondary accent.