ergative phrasal verb → block If you block something up or if it blocks up, it is blocked completely so that nothing can get through it. [V n P] ⇒ 'Any holes in the kitchen where the mice are getting through?'—'I've blocked them up.'. [V P n (not pron)] ⇒ Powdering a sweaty nose will only block up the pores and make the skin more uncomfortable. [V P] ⇒ With this disease the veins in the liver can block up, and all sorts of damage follows.
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