From thaw +‎ -ing.

• (traditional Received Pronunciation) IPA^(key): /ˈθɔː.ɪŋ/
• (Standard Southern British, intrusive R) IPA^(key): /ˈθoː.ɹɪŋ/ [ˈθoː.ɹɪŋ(ɡ)]
• (Standard Southern British, intrusive R, g-dropping) IPA^(key): /ˈθoː.ɹɪn/ [ˈθoː.ɹɪn]
• (Standard Southern British, intrusive R, th-fronting) IPA^(key): /ˈfoː.ɹɪŋ/ [ˈfoː.ɹɪŋ(ɡ)]
• (Standard Southern British, intrusive R, th-fronting, g-dropping) IPA^(key): /ˈfoː.ɹɪn/ [ˈfoː.ɹɪn]
• (General American) IPA^(key): /ˈθɔ.ɪŋ/ [ˈθɔ.ɪŋ]
• (General American, cot–caught merger) IPA^(key): /ˈθɑ.ɪŋ/ [ˈθɑ.ɪŋ]

thawing

1. present participle and gerund of thaw

thawing (plural thawings)

1. The process by which something thaws.
   • 1829, James Macauley, The natural, statistical, and civil history of the state of New York:

     Hence, there is a succession of thawings and freezings. The former expand, and endeavour to restore the surface of the ground to its natural condition, while the latter contract and harden it.