Buttoned-up and Undercover

Buttoned-up adjective - Having or showing a lack of friendliness or interest in others.

Undercover and buttoned-up are semantically related. In some cases you can use "Undercover" instead an adjective phrase "Buttoned-up".

Undercover adjective - Undertaken or done so as to escape being observed or known by others.

Buttoned-up and undercover are semantically related. Sometimes you can replace phrase "Buttoned-up" with "Undercover", this terms are similar.