Openings like these are seen on castle walls . What are they commonly called ?


Loopholes , from which the phrase takes its origin !! These are vertical slits / openings in the walls of fortifications which allow a defender to shoot or look out while remaining protected . Metaphorically , therefore , the word means a gap ,omission ,error or ambiguity that one can exploit .
( Embrasures / Arrow Loop / Arrow Slit etc accepted )
Cracked by Arun Hiregange , Rithwik , Johny Walker , Incognito , Gautam Jayasurya , Sandi , Abhi , Deepthi Mani , Yadhu , Hadi , Sai G , Abhishek Das , Arun AS , Abhijeet and Anil Raghavan .
loopholes
The term Embrasure, in military architecture, refers to the opening in a crenellation or battlement between the two raised solid portions or merlons, sometimes called a crenel or crenelle. In domestic architecture this refers to the outward splay of a window or arrow slit on the inside.The etymology of embrasure expresses widening.
Loophole / embrasure
embrasures
arrow slit???
battlements???
cesspit???
is it a arrow loop ?
Balistraria, also called arrow loop or arrow slit
arrow loop
Meurtriere: arrow loop, slit in battlement or wall to permit firing of arrows or for observation
Arrow Loop?
For shooting arrows and stuff?
eaves and hence eavesdropping?
keyhole???
loopholes
itz called the ARROW LOOP , used for allowing archers to fire with great protection!!
Balistraria/Arrow loops
Murder holes, for pouring oil on invaders
Balistraria??
Balistraria??
A loophole, arrow loop or arrow slit passes through a solid wall and was originally for use by archers.
[The sec image is An embrasure looking through the arrow slit, Caen, France]
arrow loop
keyhole?
keyhole?