Self-important and Straitlaced

Self-important adjective - Having too high an opinion of oneself.

Straitlaced and self-important are semantically related. In some cases you can use "Straitlaced" instead an adjective phrase "Self-important".

Straitlaced adjective - Given to or marked by very conservative standards regarding personal behavior or morals.

Self-important and straitlaced are semantically related. Sometimes you can use "Self-important" instead an adjective "Straitlaced".