He was in a mismatched blue jacket and trousers and his top shirtbutton was undone.
The Sun (2015)
A bit of white belly pops out between the shirtbuttons.
Times, Sunday Times (2011)
Peel and finely slice the ginger and chop into pieces the size of shirtbuttons.
Times, Sunday Times (2014)
Definition of 'button'
button
(bʌtən)Explore 'button' in the dictionary
countable noun
Buttons are small hard objects sewn on to shirts, coats, or other pieces of clothing. You fasten the clothing by pushing the buttons through holes called buttonholes.
Definition of 'shirt'
shirt
(ʃɜːʳt)Explore 'shirt' in the dictionary
countable noun
A shirt is a piece of clothing that you wear on the upper part of your body. Shirts have a collar, sleeves, and buttons down the front.