spas ‧ m /ˈspæz ə m/ BrE AmE noun
[ Date: 1300-1400 ; Language: Old French ; Origin: spasme , from Latin , from Greek spasmos , from span 'to pull' ]
1 . [uncountable and countable] an occasion when your muscles suddenly become tight, causing you pain:
Maggie felt a muscle spasm in her back.
Tom’s jaw muscles had gone into spasm.
back/shoulder/throat etc spasm
2 . spasm of grief/laughter/coughing etc a sudden strong feeling or reaction that you have for a short period of time:
I felt a spasm of fear.