(uncountable) One of several sizes to which an item may be manufactured. / (countable) An item labelled or denoted as being that size. / (countable) One who fits an item of that size.

(especially clothing) That is extra extra extra small (the manufactured size). / Used other than figuratively or idiomatically: see extra, small.

(computing) A standard interface and command set for transferring data between devices on a bus.

A SUMO protein

(idiomatic) One who has achieved a high rank or is highly esteemed, but only in a small, relatively unimportant, or little known location or organization.

plural of big fish in a small pond

plural of small Solar System body

(informal) Do not give in to petty problems; don't worry about insignificant matters.

(astronomy) A body in the Solar System other than a planet, dwarf planet or natural satellite.

Small gestures of help and kindness matter more than costly and exorbitant bestowals.