Rarefy

1.

(INTRANSITIVE) ([of air etc.] to make or become less dense than is normal) ធ្វីឲ្យតិចទៅ, ស្ដើងចុះ

2.

(TRANSITIVE) ធ្វើឲ្យហោចចុះ, រង្វើលចុះ

3.

(វេជ្ជសាស្ត្រ) (ឆ្អឹង) ក្លាយជាទន់

1.

(TRANSITIVE) To make rare, thin, porous, or less dense; to expand or enlarge without adding any new portion of matter to; -- opposed to condense.

2.

(INTRANSITIVE) To become less dense; to become thin and porous.