アラビア数字[arabiasuuji] Arabic numeral
キリル文字[kirirumoji] Cyrillic character
ギリシア文字[girishiamoji] Greek character
羅馬字[roomaji] Latin alphabet
ロシア文字[roshiamoji] Russian character

異体字[itaiji] kanji variants
一字[ichiji] letter
一字千金[ichijisenkin] word of great value
一丁字[itteiji] single letter or character
一文字[ichimonji] straight line

介添え[kaizoe] helper
寄添う[yorisou] to get close
後添い[nochizoi] one's second wife
食品添加物[shokuhintenkabutsu] food additive
申し添える[moushisoeru] to add to what has been said

添う[sou] to meet (one's expectations, etc.)
添加[tenka] addition
添加剤[tenkazai] addition agent
添加物[tenkabutsu] addition
添削[tensaku] correction