apa dhū

 apa‑dhū means “to shake off, remove, cast away,” combining the prefix apa‑ (“away, off”) with the root dhū / dhu (“to shake, agitate”).

The root dhū / dhu

The web results show that dhū (धू) and dhu (धु) are verbal roots meaning “to shake, agitate, shake off, remove, blow away, fan, or destroy”

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Key senses include:

• to shake, agitate, cause to tremble (e.g., धुन्वन्ति पक्षपवनैः…)

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• to shake off, remove, throw off

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• to blow away, destroy

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• to fan or kindle (fire)

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• to free oneself from, cast off

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  These meanings are consistent across the dictionary entries, which list the root in several conjugational classes (5th, 6th, 9th, 10th) with forms like dhunoti, dhunute, dhūnoti, dhūnute

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The prefix apa‑

Although the results do not explicitly define apa‑, it is a standard Sanskrit verbal prefix meaning:

• away, off, down, back, out
  It reverses, removes, or separates the action of the root.

Meaning of apa‑dhū

Combining the prefix with the root gives a predictable meaning:

• apa + dhū → “to shake off, remove, cast away, drive away.”

This is directly supported by the dictionary’s listing of prefixed forms:

• With ava‑ (a closely related “off/down” prefix), the root means “to shake off, remove, abandon”

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• With nir‑ (“out, away”), it means “to destroy, remove”

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• With vi‑ (“apart”), it means “to shake apart, agitate, disperse”

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Since apa‑ has the same directional force (“off, away”), apa‑dhū naturally means:
“to shake off, remove, dispel, cast away, drive away.”

Possible grammatical forms

Depending on conjugation class, apa‑dhū could appear as:

• apadhunoti / apadhunute (5th‑class or 9th‑class forms)
• apadhūnoti / apadhūnute (6th‑class forms)
• apadhūnayati (causative: “to cause to shake off”)

Summary

apa dhū in Sanskrit expresses the idea of removing something by shaking, casting off, or driving away, based on the root’s core meaning “to shake” and the prefix’s meaning “away/off.”