lick, lap up, burn up, taste, undergo, underrate, despise
甞 centers on direct sensory experience, especially tasting or licking, and by extension undergoing something firsthand. The meanings 'burn up', 'underrate', and 'despise' are less common and may be specialized or archaic applications.
甞 is a variant form of 嘗, which historically combined 旨 (delicious) with 尚 (phonetic) to express tasting. In 甞, the lower 旨 is replaced by 甘 (sweet), reinforcing the taste-related meaning.
The top part looks like a roof (冖) over a mouth (口), and the bottom is 甘 (sweet). Imagine putting something sweet under a roof into your mouth to taste it: licking and savoring the flavor.
For ショウ, picture a chef saying 'show' as he demonstrates how to taste a dish: show -> ショウ, and you lick the spoon to taste the sweet flavor.