These words mean not conforming to accepted standards of social behaviour, good taste or propriety. Indecent is the strongest word in this group. Primarily it connotes condemnation of obscenity or licentiousness: indecent remarks directed at passing school girls; indecent pictures; an indecent proposal to engage in abnormal sexual practices. In its second meaning, indecent suggests a lack of decorum and disregard for the feelings of others.

• After his wife died, he remarried with indecent haste; His appetite for gossip a absolutely indecent .

Immodest and indelicate are applied to that which shows little sense of what is fitting or acceptable in a society which sets a high price on propriety. In one sense, immodest is close in meaning to indecent , having long been applied, especially to women, when it is a question of revealing clothing or unrestrained behaviour towards the opposite sex.

• Many older people find the bikini immodest ; My mother thinks my sister is immodest because she pursues boys.

Immodest has a second meaning of aggressive and boastful: the immodest self-seeking of a social climber; to brag in an immodest way about one’s great abilities. Indelicate is not as strong a term as immodest and suggests more a lack of tact and thoughtfulness than unconventional behaviour.

• It is thought by many to be indelicate to discuss how much money one makes; Subjects fit for the club bar are sometimes too indelicate to be discussed at the family dinner table.

Improper and unseemly are used of actions or conduct that violate standards of good taste and the fitness of things.

• It is considered improper for a lawyer to discuss his clients outside his office; It would be regarded as unseemly and ridiculous for a well-known philosopher to endorse the qualities of a patent medicine.

Often improper is used as a euphemism for indecent in the sense of obscene: to make improper advances.

Indecorous is applied to conduct that does not conform to established conventions of formality and manners, conduct generally consisting of minor infractions for which any of the other words in this group would be too strong.

• Loud laughter during a wedding ceremony is indecorous ; She always felt indecorous when she was obliged to adjust a slipped shoulder strap in public.