plaster

1 plaster /ˈplæstɚ/ Brit /ˈplɑːstə/ noun
plural plasters
1 plaster
/ˈplæstɚ/ Brit /ˈplɑːstə/
noun
plural plasters
Britannica Dictionary definition of PLASTER
1 
[noncount]
a  : a wet substance that hardens when it becomes dry and that is used to make smooth walls and ceilings — often used before another noun
2 
[count] British : a piece of material that is put on the skin over a small wound

in plaster

British
: in a hard covering that protects a broken bone and allows it to heal : in a plaster cast
2 plaster /ˈplæstɚ/ Brit /ˈplɑːstə/ verb
plasters; plastered; plastering
2 plaster
/ˈplæstɚ/ Brit /ˈplɑːstə/
verb
plasters; plastered; plastering
Britannica Dictionary definition of PLASTER
[+ object]
1 
a  : to cover (a surface) with plaster
b  : to cover (a surface or area) with something — usually used as (be) plastered
2 
: to put (something, such as a poster or sign) on a surface
— often used figuratively
3 
: to make (something) lie flat against or stick to something

plaster over

[phrasal verb]
plaster over (something) or plaster (something) over
: to cover (something) with plaster