window-min-size

window-min-size is a compiled Lisp function in `window.el'.

(window-min-size &optional WINDOW HORIZONTAL IGNORE PIXELWISE)

Return the minimum size of WINDOW.
WINDOW must be a valid window and defaults to the selected one.
Optional argument HORIZONTAL non-nil means return the minimum
number of columns of WINDOW; otherwise return the minimum number
of WINDOW's lines.

The optional argument IGNORE has the same meaning as for
`window-resizable'. Optional argument PIXELWISE non-nil means
return the minimum pixel-size of WINDOW.