Qenya
penda
adjective. sloping down, inclined
am(ba)penda
adjective. uphill, uphill, *sloping up; [ᴱQ.] arduous, difficult, tiresome
ampenda
adjective. uphill
yanta
noun. bridge
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
An adjective meaning “uphill” in The Etymologies of the 1930s with variants ambapenda and shorter ampenda, a combination of amba “up(wards)” and penda “sloping” (Ety/AM²). More literally it means “✱sloping up”, versus plain penda which has an implication of “sloping down”. It also appeared in the Early Noldorin Dictionary of the 1920s as ᴱQ. ambapenda, where its cognate ᴱN. amvenn had the glosses “uphill; arduous, difficult, tiresome” (PE13/159). Perhaps ᴹQ. am(ba)penda could colloquially have these meanings as well.