gentlesir 

Usually young white beta-males who live on Reddit or 4Chan. They wear fedoras with t-shirts. They open doors for women ("m'lady") or do other nice things not because they're polite people, but because they want to get laid.

Also related: talking about getting friend-zoned, loving V for Vendetta, libertarian politics, thinking they're the smartest person in the chatroom, basement dwelling, etc.

The gentlesir tipped his hat to m'lady and opened the door for her. She was just a random bystander and walked in without acknowledging him. He muttered to himself about how rude women were these days before checking the Reddit thread about anarchism.

gentlesir by ungentlesir January 8, 2016

Gentle Femdom 

A subset of the Femdom family of kinks that emerged in rejection of (what was perceived to be) an unrealistically male-centered, violent, and unsentimental kind of femdom content that is popular on mainstream porn sites.

The gentle femdom community has substantial following on tumblr, reddit, and 4chan, with it's largest presence being on tumblr.

Lisa: I love gentle femdom, femdom is usually too much for me.

Gentle Femdom by lil-boy-bubblegum October 7, 2017

gentleman style 

In order to perform in gentleman style, a man must be wearing a top hat and a Mr. Peanut mono-lens eyeglass. In addition, he must perform his thrusts with his fists on his hips, and say "oh dear" when he has an orgasm.

Peter North knows nothing of gentleman style.

gentleman style by bjergen May 24, 2007

gentleman's knife 

A knife that is appropriate to carry with business attire in an urban environment. It's functional and classy without being tactical looking (i.e., without unnecessary, menacing, mall ninja-type features).

Every man should have a classy watch and a reliable gentleman's knife.

gentleman's knife by Jake McCoy November 18, 2011

Gentlemanly 

/ˈjen(t)lmənlē/
1. adj. a word used to describe a being who displays behavior commonly associated with that of a gentleman

The gentlemanly man (as of August, 26 2015) emerged from his house with an umbrella to escort his lovely girlfriend into the house; despite the rain.

Gentlemanly by Jiska _ October 9, 2015

Pittsburgh Gentleman

A mixed drink consisting of Crown Royal, ginger ale, lime juice, and grenadine.

After a long day at the office, I like to put back a series of Pittsburgh Gentleman to take the edge off.

Pittsburgh Gentleman by Pburgh73 September 30, 2011

Gentleman's Bet 

A wager on principle rather than for significant amounts of money.

A typical Gentleman's Bet will be for no money or a nominal sum (e.g., $1) with the "prize" of being correct going to the winner. Think of Trading Places and the bet the Duke brothers made.

Gentleman's Bet by thesellman April 16, 2014