Possible Clues:

• Waver, go this way and that
• Go up and down
• Irregularly rise and fall
• Rise and fall irregularly
• Swing
• Illness, horribly acute, in which temperature's seen to go up and down
• Vary irregularly, as prices
• Shift back and forth
• Having influenza, see tea you ate will keep changing
• Wind instrument with suitable cut put by one inside makes seesaw