There are two gibbous phases: waxing and waning (growing and shrinking). The waxing phase occurs just before the full moon, and in the northern hemisphere the shadow will appear on the left side (see animation).
Lana Kane: [...] we're standing in a cranberry bog of blood!
Archer: Well, it is a full moon, so --
Cecil Vandertunt: It's actually a waxing gibbous.
Adam Reed. Archer, season 8, Dreamland: Waxing Gibbous (2017)
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Something of daylight still lingered, and the moon was waxing bright: I could see him plainly.
Charlotte Brontë. Jane Eyre (1847)
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“Not wi’ child yet?” she demanded. “Raspberry leaves, that’s the thing. Steep a handful wi’ rosehips and drink it when the moon’s waxing, from the quarter to the full. Then when it wanes from the full to the half, take a bit o’ barberry to purge your womb.”