deadpan snarker
― a character prone to gnomic, sarcastic, sometimes bitter, occasionally whimsical asides

action girl
― tough female badass who kicks ass

drowning in sorrows
― whenever they stressed, angry or sad, they reach for the bottle

the runaway
― a character who runs away from her home and/or parents

femme fatale
― deadly woman

mercy kill
― ending the life of a person suffering

tomboyish ponytail
― action hair for and action girl

bartender
― a character who worked in a bar

bruiser with a soft centre
― a character whose hands can smash through walls effortlessly now rise to hide the tender tears, or remain stoically at his sides as he weeps 'manly' tears.

knife nut
― a character who loves and specialises in the weaponry of knives

brutal honesty
― will tell you the truth even if it hurts your feelings

the alcoholic
― drinks way too much and may not be aware that they're behaving like an addict

sir swears-a-lot
― some characters really like the f word

bad dreams
― a character who can't escape the bad dreams

beauty, brains and brawn
― someone who is all three

definitions and tropes found on tvtropes.org (some definitions by me)