rush candle
/ˈrʌʃ ˌkandl/noun
1A candle of little power made by dipping the pith of a rush in tallow or some other grease.
2 Figurative and in figurative contexts. Something weak, feeble, or insignificant.
Origin
Mid 16th century; earliest use found in William Salesbury (d. c1580), translator and humanist scholar. From rush + candle.