the.com/standup

means A style of live comedy where a solo performer talks directly to an audience, relying on timing and writing rather than character or costume; also, slang for someone dependably honest and loyal.

from Straightforward compound of 'stand' and 'up' — literally describing the comedian's posture: alone, upright, no scene partners, no desk to hide behind, unlike the seated sketch or vaudeville acts it grew out of in the 20th century. The 'reliable, upright person' sense (a 'standup guy') comes from the same literal image of someone who stands up — for themselves, for others, under pressure — rather than ducking or caving.