हस्

There is a wide variety of variation in Indo-Aryan forms, as well as in a possible connection to Iranian. An attempt is made to explain their development below. The best way to formally reconcile these varied forms is to reconstruct Proto-Indo-Iranian *ǰʰas-, from Proto-Indo-European *gʰes-.^[1][2] This root's descendants have only been found in Indo-Iranian, and it may have origins as a natural exclamation, though this is difficult to prove.^[3]

• Sanskrit जाहस्यते (jāhasyate, intensive): Proto-Indo-Aryan *źʰā́-źʰas-ya-tay → *źā́źʰasyatay well described by Grassmann's law. This offers initial evidence for the initial consonant of the root being *źʰ.
• Vedic Sanskrit जक्षतः (jákṣataḥ, masculine plural present participle), Pali jagghati (reduplicated thematic present):

  PIE: *gʰé-gʰz-o-

  → pre-PII: *ǰʰágʰza-

  → PII: *ǰʰágžʰa- (assimilation of aspiration; may have occurred earlier)

  → PIA: *źʰágẓʰa- (TST assimilation)

  → OIA: *źágẓʰa- (Grassman's law)

  → Vedic: जक्ष- (jákṣa-); MIA: jaggha-

• Vedic Sanskrit जज्झतीः (jájjhatīḥ, feminine plural present participle), a dialectal form in the Rigveda, albeit formally cognate with जक्षतः (jákṣataḥ), is difficult to fit into this paradigm. Perhaps metathesis can explain it.

  PIE: *gʰé-zgʰ-o-

  → pre-PII: *ǰʰázǵʰa-

  → PII: *ǰʰázȷ́ʰa-

  → PIA: *źʰáźȷ́ʰa-

  → OIA: *źáźȷ́ʰa-

  → Vedic: *जज्झ- (jájjha-)

• Avestan 𐬘𐬀𐬵𐬌𐬐𐬁 (jahikā, “prostitute”), 𐬘𐬀𐬵𐬍 (jahī) is often tied to this root,^[1] given the similar Sanskrit हस्रा (hasrā́, “prostitute”) from this root. This is not uncontroversial.^[4] Tentatively, it is possible that this is a feminine diminutive nominal Proto-Iranian *ǰahikā, from Proto-Indo-Iranian *ǰʰas-ikā.
• Avestan 𐬰𐬀𐬒𐬌𐬌𐬀 (zax́iia) has been interpreted to mean "laughable" and is mentioned as the formal cognate of हास्य (hāsya)^[5] but this interpretation is uncertain.^[6] Moreover, there are formal problems as 𐬰𐬀𐬒𐬌𐬌𐬀 (zax́iia) reflects a Proto-Indo-Iranian *ȷ́ʰas- from a Proto-Indo-European *ǵʰes-.