Possible Clues:

• Armpit (anag)
• Make known or convey information to
• I am not wholly able to pass it on
• That'll teach you how I'm not all there
• Reveal devilish skill
• Give - relate
• Although not all there, I may still teach
• Although not all there, I can pass on what knowledge I have
• Convey information to
• Not being all there, I can teach