expand

Etymology

Recorded in Middle English since 1422 (as expanden, expaunden), from Anglo-Norman espaundre, from Latin expandere present active infinitive of expandō (“to spread out”), itself from ex- (“out, outwards”) + pandō (“to spread”). Doublet of spawn.

verb

1. (transitive) To change (something) from a smaller form or size to a larger one; to spread out or lay open.
   You can expand this compact umbrella to cover a large table.
2. (transitive) To increase the extent, number, volume or scope of (something).
   A flower expands its leaves.
   This has evidently been encouraging, for the current winter timetable - not even with the benefit of summer holiday traffic - shows that the two trains each way have been expanded to four. 1961 October, “The winter timetables of British Railways: Scottish Region”, in Trains Illustrated, page 594
3. (transitive) To express (something) at length and/or in detail.
4. (transitive, algebra) To rewrite (an expression) as a longer, yet equivalent sum of terms.
   Use the binomial theorem to expand (x+1)⁴.
5. (intransitive, algebra, of an expression) To become, by rewriting, a longer, yet equivalent sum of terms.
   The expression (x+1)⁴ expands to x⁴+4x³+6x²+4x+1.
6. (transitive, arithmetic) To multiply both the numerator and the denominator of a fraction by the same natural number yielding a fraction of equal value
7. (intransitive) To change or grow from smaller to larger in form, number, or size.
   Many materials expand when heated.
   This compact umbrella expands to cover a large table.
8. (intransitive) To increase in extent, number, volume or scope.
9. (intransitive) To speak or write at length or in detail.
   He expanded on his plans for the business.
   There was some laughter, and Roddle was left free to expand his ideas on the periodic visits of cowboys to the town. “Mason Rickets, he had ten big punkins a-sittin' in front of his store, an' them fellers from the Upside-down-F ranch shot 'em up […]” 1899, Stephen Crane, chapter 1, in Twelve O'Clock
10. (intransitive) To feel generous or optimistic.