This complex medical word is formed by the combination of two root terms: [dacry-] meaning "tear" and [-cyst-], meaning "sac". The combined root [dacryocyst-] means "tear sac" or better, "lacrimal sac" (the Latin word [lacrima] means "tear"). This medical word also has a combined suffix: [-(o)lith], meaning "stone", and [-iasis], meaning "disease or condition".
The word [dacryocystolithiasis] means then, "a condition or pathology of stones (calculi) in the lacrimal sac". The procedure to remove the stones would then be called a [dacryocystolithectomy].