- 簡単【かんたん】 - simple, easy, uncomplicated, brief, quick, light 
- 単純【たんじゅん】 - simple, plain, uncomplicated, straightforward, simple-minded, naive 
- 単なる【たんなる】 - mere, simple, sheer 
- 単位【たんい】 - unit, denomination, credit (in school), in units of (e.g. "in thousands"), in amounts of 
- 単に【たんに】 - simply, merely, only, solely 
- 単語【たんご】 - word, vocabulary 
- 単独【たんどく】 - sole, single, solo, independence, singleness, singularity 
- 単一【たんいつ】 - single, simple, sole, individual, unitary 
- 単行本【たんこうぼん】 - standalone book (i.e. not part of an anthology, series, etc.), (book published as a) single volume, tankōbon, individual volume of a manga series 
- 単調【たんちょう】 - monotony, monotone, dullness, monotone, monotonic 
- 単身【たんしん】 - alone, unaided, away from home 
- 単価【たんか】 - unit price, unit cost 
- 単産【たんさん】 - (single-industry) industrial union 
- 単発【たんぱつ】 - firing one shot at a time, single-shot gun, having only one engine, single-engined aeroplane, single-engined airplane, one-shot (e.g. story), non-serial, one-off, single occasion 
- 単勝【たんしょう】 - winning at the races 
- 単純化【たんじゅんか】 - simplification 
- 単線【たんせん】 - single track (railway), single line, solid wire, solid-core wire, single-strand wire 
- 単純平均【たんじゅんへいきん】 - simple average, arithmetic average 
- 単体【たんたい】 - simple substance (e.g. chemical), something standing alone, separate item, solo item 
- 単色【たんしょく】 - single colour (color), monochrome