礼れいを尽つくす

expression, godan verb (-su)

be extremely polite; show utmost courtesy; do everything etiquette requires

Used when someone goes to great lengths to observe proper manners, often in formal or ceremonial contexts.

• 彼かれは目め上うえの人ひとに礼れいを尽つくして接せっする。

  He treats his superiors with the utmost courtesy.

• 結けっ婚こん式しきでは、両りょう家けの親しん族ぞくに礼れいを尽つくすことが大たい切せつだ。

  At a wedding, it is important to show every courtesy to the relatives of both families.