This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
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adj. Of or pertaining to the tergum; dorsal

adj. Of or pertaining to back, or tergum. See dorsal.

Of or pertaining to the back in general; dorsal; notæal: the opposite of sternal or ventral. Specifically

In entomology, of or pertaining to a notum, tergum, or tergite.

In echinoderms, dorsal in the sense of aboral; coronal: the opposite of ventral or oral: as, the tergal plates of a starfish.

In trilobites, of or pertaining to the axis or tergum. See cut under Trilobita.

"The scutal depressor muscles, the scutal abductor muscle, and the tergal depressor muscle are used to open and close the two plates that cover the opening to the barnacle."

tergal facet   

dorsal