Towards the completion of its growth a more or less prominent ring of bone, termed the burr or coronet, is deposited at its base just above the junction with the pedicle; this ring tending to constrict the blood-vessels, and thus cut off the supply of blood from the antlers...

You either have to move the bra straps down your shoulders in order to expose your breasts, or you have to raise your bra, which can constrict your breasts causing you discomfort.

If you are taking medicines for allergies or a cold, stay away from medicines that promote sleepiness as this can cause the throat to relax too much and constrict the airway.

If you plan to layer garments, consider buying your women's plus size rain coat one size larger than you normally wear for a roomy, comfortable fit that does not constrict your range of motion.

It is often most obvious in flash photographs; since the pupil is exposed to a lot of light and the duration of the exposure is so short, the pupil does not have time to constrict.