Thridace is a rare, obsolete word that is spelled as [θrɪdəs] in IPA phonetic transcription. The first syllable "thri" is pronounced with a voiceless dental fricative "θ" followed by the vowel sound "ɪ" and a voiced dental consonant "d". The second syllable "dace" is pronounced with the vowel sound "ə" and the voiceless dental fricative "s". This word is believed to have originated from Middle English and means "a third part," but its usage is limited today.