UBS Dictionary of the Greek New Testament

Sense 1: grain, food

Semantic entry: 3.42

Semantic domains: Plants

Subdomains: Fruit Parts of Plants

Definition: (a diminutive form of σῖτος ‘grain,’ 3.41: σῖτος, but not diminutive in meaning) any grain, but with the evident implication of its relevance as food.

Notes: (See also 5.2: σιτίον.) On the basis of this one NT occurrence it is impossible to know whether the meaning of σιτία is ‘grain’ or ‘food,’ since in the phrase σιτία καὶ ποτά ‘food and drink’ (an expression occurring in a number of extrabiblical contexts), the term σιτίον contrasts solid with liquid nourishment.

Further resources: flora:3.1.4

Sense 2: food, grain

Semantic entry: 5.2

Semantic domains: Foods and Condiments

Subdomains: Food

Definition: (diminutive of σῖτος[a] ‘wheat, grain,’ 3.41: σῖτος, but without diminutive meaning and occurring primarily in the plural) food consisting principally of grain products

Notes: It is, of course, possible in RV ACT 7:12 · LV ACT 7:12 · Read together ACT 7:12 to understand the plural form as ‘grain’ (see 3.42: σιτίον), but the reference is probably to food made from grain, a common meaning of this term in Classical Greek.