Definition of blockers:
(n) :
Agent noun of block (“obstruct or prevent”); something that blocks something else.
(n) :
(sports) One who blocks or impedes the movement of an opponent.
(n) :
(computing) An application that stops / impedes unauthorised access to a programme.
(n) :
(computing) One who prevents another user from contacting them electronically.
(n) :
(biology, medicine) Any of various medications that block (inhibit) the activity of a chemical messenger or its receptors, such as cardiac conduction modifiers (e.g., alpha-blockers, beta-blockers), gastric acid inhibitors (H₂ histamine blockers), puberty blockers, and others.
(n) :
(cricket) A defensive or low-scoring batter.