From Japanese-English FreeDict Dictionary ver. 0.1:
[ichi1] [news1] [nf16] 熟 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, 熟熟 /(en)tʃˈaɪniːz(ja)lˈe̞tə (en)tʃˈaɪniːz(ja)lˈe̞tə/, 熟々 /(en)tʃˈaɪniːz(ja)lˈe̞tə lˈe̞təsˈänɹˈe̞iɹˈe̞iɡˈo̞/, [ichi1] [news1] [nf16] つくづく /tsˌɯᵝkɯᵝzˈɯᵝkɯᵝ/, つくつく /tsˌɯᵝkɯᵝtsˈɯᵝkɯᵝ/
(adjectival nouns or quasi-adjectives (keiyodoshi))
(adverb (fukushi))
Note: word usually written using kana alone
Note: onomatopoeic or mimetic wordcompletely, really, thoroughly, deeply, severely, intently