verb transitive: 1. to adopt or support a cause, idea, belief, etc.
2. to take as spouse: marry
From Old French espouser, from Latin sponsare (to betroth), from sponsus (betrothed). Ultimately from the Indo-European root spend- (to make an offering or perform a rite), which is also the source of sponsor, spouse, respond, and riposte. Earliest documented use: 1477
Usage (from Wordsmith)
“Chevy Eugene’s research focuses on the arts as a key tool for Caribbean integration — an idea he not only espouses, but actively pursues.”
Time for a New Kind of Black Activism; Toronto Star (Canada); Apr 19, 2015.