to yawn is a form of:

Yawn



noun
1.
(វេជ្ជសាស្ត្រ) ការស្ងាប
verbpast tense: yawned ; past participle: yawned ; present participle: yawning ;
1.
(វេជ្ជសាស្ត្រ) ស្ងាប
2.
(INTRANSITIVE) (to open the mouth wide and draw in breath (often involuntarily), to have a wide opening to form a chasm) ស្ងាប
ENGLISH MEANING
noun
1.
An involuntary act, excited by drowsiness, etc., consisting of a deep and long inspiration following several successive attempts at inspiration, the mouth, fauces, etc., being wide open.
2.
The act of opening wide, or of gaping.
3.
A chasm, mouth, or passageway.
verbpast tense: yawned ; past participle: yawned ; present participle: yawning ;
1.
(INTRANSITIVE) To open the mouth involuntarily through drowsiness, dullness, or fatigue; to gape; to oscitate.
2.
(INTRANSITIVE) To open wide; to gape, as if to allow the entrance or exit of anything.
3.
(INTRANSITIVE) To open the mouth, or to gape, through surprise or bewilderment.
4.
(INTRANSITIVE) To be eager; to desire to swallow anything; to express desire by yawning; as, to yawn for fat livings.