Definition: prompt, responsive, cheerful and ready to help
Why I Looked It Up
In Uncle Tom’s Cabin:
This personage had been exerting himself, with great alacrity, in driving all the flock of domestics to the other end of the veranda.
A theme of the book, in fact, is how some slaves in the South exhibited this type of subservience to their oppressors. In fact, the title character – Uncle Tom, himself – was received poorly by some people who claim that his willingness to be subservient, instead of defiant and resistant, was a poor reflection on the state of slavery.
Added on May 3, 2023
From the spy novel Eurostorm:
Then he nodded toward the distant illumination and said with alacrity, “Those are the coastal lights of Tel Aviv.”