词根词缀：pre-, prae-

【来源及含义】Latin: before [both in time and place]

【相关描述】The prefix prae- can actually be substituted for pre- because both of them are different spellings for the same prefix meaning "before".

【相关词根词缀】 Related before-word units: ante-; antero-; anti-; pro-. Related "time" units: aevum, evum; archaeo-, archeo-; Calendars; chrono-; horo-; Quotes: Time; tempo-.

【同源单词】preacquaint, preacquaintance, preagonal, pre-agricultural, preamble, preambular

词根词缀：presby-, presbyo-

【来源及含义】Greek: old, relationship to old age, elderly, elder; literally, "he that goes first"

【相关词根词缀】 Related "old; old age, elder" units: gero-; obsolesc-; sen-; veter-.

【同源单词】elder, elder share, presbyasomnia, presbyatrics, presbycardia, presbycusis

词根词缀：somni-, somno-, somn-, -somnia, -somniac

【来源及含义】Latin: sleep, sleeping; dreams, dreaming

【相关词根词缀】 Related "sleep" units: dorm-; hypno-; letho-; narco-; oneiro- (dream); sopor-.

【同源单词】cacosomnia, dyssomnia, dyssomniac, dyssomniac, hypersomnia, hypersomniac