遠慮会釈
en.ryo.e.shaku
Literally: far – thought – meet – explain
Alternately: Holding back and thinking of others; reserve and consideration.
Notes: This is a compound of compounds; 遠慮 is “discretion,” “restraint,” and 会釈 is “thoughtfulness (for the sake of others.” These parts may also be switched to give 会釈遠慮 (eshaku enryo). The phrase may be negated to give the critical phrase 遠慮会釈も無い (enryo eshaku mo nai), “arrogant,” “inconsiderate,” or even “ruthless.” Finally, 傍若無人 is considered an antonym.
I’m actually cheating a bit here. Strictly following the iroha ordering means that this week’s compound should start with を (wo). But while the iroha karuta sets themselves tell us that words like 鬼 used to be をに, I’ve found it a lot harder to find four-character compounds that use a reading that begins with を (cf. phrases like 百鬼夜行 (hyakki yagyou); almost all yojijukugo use the Chinese-style reading in this fashion).
The approach I’m taking is based on kana derivations: we know that every kana sign is the simplified form of a kanji, so the mere existence of kana for wo means there must be kanji that can be read as wo per se. In this case, the katakana “wo” (ヲ) is derived from 乎, and the hiragana を is derived from 遠. That said, it seems pretty clear to me that this を is the analog of the modern Japanese-style reading o rather than anything that actually appears in a yojijukugo. Ultimately I feel like this is an え entry acting as a placeholder because for purposes of our series, no true を entry seems to exist, but it’s the best I could muster with limited time and resources.

By extension, an 会釈 is also a very precisely defined style of bow