LA
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Note that la also means mountain pass, like the infamous Thorung La pass in case you have ever done the Annapurna trek in Nepal, and got stuck on this pass where there seems to be a constant snow storm, that in combination with altitude weakness and badly peeled apples, oh well. Anyway, you could easily see from the context if la is a particle (very common) or la the mountain pass (less common).
la is also the letter. Speaking of the alphabet, sometimes you see the expression a li ka li, this is referring to the Sanskrit vowels and consonants, especially in tantric meditations.