Of or pertaining to substitution or to a substitute

Non-Oxford British English standard spelling of subsidize.

(Greek orthography) A small iota written below an alpha, eta or omega – e.g. in ᾠδή (ōidḗ) – representing a vocalic offglide that was pronounced in early Ancient Greek, but later became silent; invented in the Middle Ages in order to mark those vowels which would originally have had such an offglide.

(zoology) chemical given off from the skin of a fish after injury that warns nearby fish of danger.

(law) The statutory or written law that governs rights and obligations of those who are subject to it.

Liquid that replaces milk in a diet or recipe.

(grammar) An adjective used alone in the absence of the noun that it modifies.

A food additive that replicates the sweetness of sugar but is not sugar.

A subsequent act or thing; a sequel. / The state of being subsequent.

(mathematics) A sequence that is contained within a larger one. / (computer science) A subset of an array with the same ordering.