Small enough to fit in the palm of one's hand.
"I'm not really interested in the big ones, I'm more into those that are palmable"
A man's ability to hold the weight of a woman on one hand/wrist while making love to her in a standing position. A man and a woman having sex while the woman is elevated from the ground with her weight primarily resting on the man's one hand/wrist. Best occurs when the man is strong and the woman is petite or knows how to balance her weight. Typically isn't successful when skinny guys or fat chicks are involved.
Shane grabbed the palmable maid as she was getting out of the shower and was able to thrust her back and forth using one hand Malibu Express style.
Brad thought the chunky girl he hooked up with at the bar was palmable, but she ended up breaking his wrist as they got it on.