-io

an action, process, or result

Forms

-io
-ion- — The longer form used before Latin endings.
-ion — The form carried into many English nouns.

Origin

An old Latin noun ending, inherited from earlier Indo-European word formation.

Note

The ending can name both an activity and what that activity produces.

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noun

convulsion

kun-VUL-shun/kənˈvʌlʃn/

A sudden uncontrolled violent movement.

A sudden convulsion shakes his body as the nurse approaches.

Adult in a seizure lying safely on side with a folded jacket under head and concerned caregiver keeping area clear, no restraint or object in mouth, educational restrained.

Etymology

conLatintogether, with; sometimes thoroughly

+vulsLatinto pluck or pull

+ionLatinan action, process, or result

The pieces underlie a Latin verb meaning “to tear loose,” giving convulsion an image of violent pulling. The noun described involuntary muscular contractions before extending to violent turmoil in a society or group.

In context

Libranima550:40

His face worked, as though in convulsion.

Crime and Punishment - Dostoevsky (Illustrated Audiobook) Part 1 of 2

More examples

The child has convulsions during a high fever.
Her arms jerk with each convulsion.
The war throws the region into political convulsions.

Forms

convulsion · convulsions

convulse verb — To shake with sudden, uncontrolled movements.

convulsive adjective — Involving sudden, violent, involuntary muscle movements.

Similar words

spasm: Can involve a single muscle and need not be violent.
seizure: An episode of abnormal brain activity that may cause convulsions.