gentleman
n. countable B1 Intermediate Oxford US //ˈdʒɛnəɫmən// UK //dʒˈɛntəlmən// gen·tle·man
n. a man who is polite, honest, and treats other people with respect. You can also use it as a formal way to address or talk about any man.
n. a man of refined manners and high standards of conduct; also used as a formal or polite designation for any male. Historically associated with high social status or land ownership, though modern usage focuses on chivalrous behaviour.
He is a true gentleman and always holds the door open.
The host asked the gentleman in the front row to stand up and introduce himself to the group.
From Middle English gentilman, morphologically gentle + man, partial calque of Old French gentilhome.
Usage
Often used in the plural 'gentlemen' as a formal vocative in speeches or on signage for public facilities.