triatomic /trī-ə-tomˈik/

1. Consisting of three atoms
2. Having three replaceable atoms or groups
3. Trivalent

• mourners
• mournful
• mournfully
• mournfulness
• mournfulnesses
• mourning
• mourning band
• mourning bands
• mourning border
• mourning borders
• mourning-bride
• mourning-brides
• mourning cloak
• mourning cloaks
• mourning coach
• mourning coaches
• mourning dove
• mourning doves
• mourningly
• mourning piece
• mourning pieces
• mourning ring
• mourning rings
• mournings
• mourning-stuff