nuquerna adj. "reversed", or perhaps rather *"turned upside down". Attested in the phrases silmë nuquerna and árë nuquerna, q.v.
Quenya
nuquerna
adjective. reversed, inverted, *(lit.) under-turned
nuquerna
reversed
silmë nuquerna
noun. s-reversed
árë nuquerna
noun. árë-reversed
A word meaning “reversed” (LotR/1123) or “inverted” (PE22/49) in the names of the tengwar árë nuquerna and silmë nuquerna. It appears to be a combination of nu “under” and an adjectival form querna of the verb quer- “turn”, so more literally “✱under-turned”. Thus it only means “reversed” in a vertical direction, and “inverted” is a more accurate translation.