1 The Hebrew is דַעַת־רוּחַ (da’at-ruakh). This means knowledge without any content, vain knowledge.
2 The image is rather graphic. It is saying that he puffs himself up with the wind and then brings out of his mouth blasts of this wind.
3 The word for “east wind,” קָדִים (qadim), is parallel to “spirit/wind” also in Hos 12:2. The east wind is maleficent, but here in the parallelism it is so much hot air.
4 The infinitive absolute in this place is functioning either as an explanatory adverb or as a finite verb. Eliphaz draws on Job’s claim with this word (cf. Job 13:3), but will declare it hollow.
5 The verb סָכַן (sakhan) means “to be useful, profitable.” It is found 5 times in the book with this meaning. The Hiphil of יָעַל (ya’al) has the same connotation. E. LipinÃski offers a new meaning on a second root, “incur danger” or “run risks” with words, but this does not fit the parallelism ( 21 [1980]: 65–82).
6 The word פָּרַר (parar) in the Hiphil means “to annul; to frustrate; to destroy; to break,” and this fits the line quite well. The reflects G. R. Driver’s suggestion of an Arabic cognate meaning “to expel; to banish” (“Problems in the Hebrew text of Job,” 3 [1955]: 77).
7 Heb “fear,” “reverence.”
8 The word גָּרַע (gara’) means “to diminish,” regard as insignificant, occasionally with the sense of “pull down” (Deut 4:2; 13:1). It is here that Eliphaz is portraying Job as a menace to the religion of society because they dissuade people from seeking God.
9 The word שִׂיחָה (sikhah) is “complaint; cry; meditation.” Job would be influencing people to challenge God and not to meditate before or pray to him.
10 The verb אַלֵּף (’allef) has the meaning of “to teach; to instruct,” but it is unlikely that the idea of revealing is intended. If the verb is understood metonymically, then “to inspire; to prompt” will be sufficient. Dahood and others find another root, and render the verb “to increase,” reversing subject and object: “your mouth increases your iniquity.”
11 Heb “tongue.”
12 The word means “shrewd; crafty; cunning” (see Gen 3:1). Job uses clever speech that is misleading and destructive.
13 The Hiphil of this root means “declare wicked, guilty” (a declarative Hiphil), and so “condemns.”
14 The verb עָנָה (’anah) with the ל (lamed) preposition following it means “to testify against.” For Eliphaz, it is enough to listen to Job to condemn him.

In other versions

ESVEnglish Standard Version

“Should a wise man answer with windy knowledge,

and fill his belly with the east wind?

Should he argue in unprofitable talk,

or in words with which he can do no good?

But you are doing away with the fear of God

and hindering meditation before God.

For your iniquity teaches your mouth,

and you choose the tongue of the crafty.

Your own mouth condemns you, and not I;

your own lips testify against you.

NIVNew International Version (2011)

“Would a wise person answer with empty notions

or fill their belly with the hot east wind?

Would they argue with useless words,

with speeches that have no value?

But you even undermine piety

and hinder devotion to God.

Your sin prompts your mouth;

you adopt the tongue of the crafty.

Your own mouth condemns you, not mine;

your own lips testify against you.

CSBChristian Standard Bible

Does a wise man answer with empty counsel

or fill himself with the hot east wind?

Should he argue with useless talk

or with words that serve no good purpose?

But you even undermine the fear of God

and hinder meditation before him.

Your iniquity teaches you what to say,

and you choose the language of the crafty.

Your own mouth condemns you, not I;

your own lips testify against you.

NLTNew Living Translation

“A wise man wouldn’t answer with such empty talk!

You are nothing but a windbag.

The wise don’t engage in empty chatter.

What good are such words?

Have you no fear of God,

no reverence for him?

Your sins are telling your mouth what to say.

Your words are based on clever deception.

Your own mouth condemns you, not I.

Your own lips testify against you.

LEBThe Lexham English Bible

“Should the wise answer with windy knowledge,

and should he fill his stomach with the east wind?

Should he argue in talk that is not profitable

or in words with which he cannot do good?

“What is worse, you yourself are doing away with fear,

and you are lessening meditation before God.

For your iniquity teaches your mouth,

and you choose the tongue of the crafty.

Your mouth condemns you, and not I;

and your lips testify against you.

KJV 1900King James Version

Should a wise man utter vain knowledge,

And fill his belly with the east wind?

Should he reason with unprofitable talk?

Or with speeches wherewith he can do no good?

Yea, thou castest off fear,

And restrainest prayer before God.

For thy mouth uttereth thine iniquity,

And thou choosest the tongue of the crafty.

Thine own mouth condemneth thee, and not I:

Yea, thine own lips testify against thee.

Public Domain