undersized (adj.)

• bantam
• bony
• dumpy
• dwarfish
• elfin
• flat
• gangling
• gangly
• gaunt
• gawky
• incipient
• lank
• lanky
• lean
• little
• meager
• midget
• petite
• rawboned
• rudimentary
• runty
• scraggy
• scrawny
• scrubby
• short
• shriveled
• shrunken
• skeletal
• skinny
• slight
• small
• spare
• spidery
• spindly
• squat
• stunted
• tiny
• twiggy
• underdeveloped
• undersize
• underweight
• undeveloped
• wizened