un·der·ac·tive 
(ŭn′dər-ăktĭv)
(ŭn′dər-ăktĭv)adj.
Characterized by insufficient or abnormally low activity: an underactive area of the brain.
un′der·ac·tivi·ty (-ĭ-tē) n.
- pull strings
- pull strings/wires
- pull-tab
- pull the plug on
- pull the rug from under
- pull the rug (out) from under
- pull the rug out from under
- pull the string
- pull the wool over eyes
- pull the wool over (someone's) eyes
- pull the wool over someone's eyes
- pull through
- pull together
- pull together
- pullulate
- pullulation
- pull up
- pull-up
- pull up stakes
- pull weight
- pull wires
- pull/yank (someone's) chain
- pulmonary
- pulmonary artery
- pulmonary function test