the.com/candlestick

means A holder with a socket or spike that keeps a candle upright and catches its drips while it burns.

from A straightforward compound from Old English candel (itself borrowed from Latin candela, 'candle,' from candere, 'to shine or glow white') plus stick, meaning a stick or support to hold something — in this case, a slender shaft to hold a candle upright. The financial chart sense is a much later borrowing: 'candlestick charts' are so named because each bar, with its thin wick-like lines and thicker body, looks like a little candle standing on the price axis.