It is referred to a loose fitting two-piece garments for women, men and children. a. Bathrobe
b. Nightshirt
c. Nightgown
d. Pajama​

Pajamas - traditionally loose fitting, two-piece garments for women, men and children.

Explanation:

your word would be isle.

isle is an island or peninsula especially a small one.

if you add the letter "a" you get aisle, which is a passage between 2 rows of something like chairs, shelves, or something else.