The single women or men that are still available for marriage in their late 30s and 40s. Sometimes they come with woundedness or baggage as pretty much all the good ones have already been hitched (but not all have been hitched, so don't lose hope).
"Dude, its tough for me to find someone to marry. The pickings are few at my age."
few choices, in general. Possibly, no choices at all (understatement). Pickings = the things you have available to pick. Slim = thin, few, small. Also slim pickens, slim pickings.
do not argue with stupid, naive, not the brightest lightbulb in the chandelier people ; most often than not the pickings are slim and you end up wasting your time.
When you see a guy/girl across the room and just know that they are an easy fuck. To fully identify a person who is easy pickings you have to take a selfie in bed with them, then title it 'easy pickings' and send to all your friends. If they allow this they are easy pickings, if they get angry and leave, they are still probably easy pickings.
Me:Oi mate did you see that dead average girl I fucked last night?
Jack: yeah mate opened the Snapchat selfie when I woke up this morning
Me:ahahaha such easy pickings