sad vs unfun

sad

• Unfashionable; socially inadequate or undesirable. 

• Soggy (to refer to pastries). 

• Causing sorrow; lamentable. 

• Of colours: dark, deep; later, sombre, dull. 

• Appearing sorrowful. 

• Feeling sorrow; sorrowful, mournful. 

• Poor in quality, bad; shameful, deplorable; later, regrettable, poor. 

unfun

• Not fun. 

• Lack or absence of fun; funlessness.