Proto-Indo-European Roots

Root/Stem: *lei-
Meanings:  to pour, to flow
Hellenic Greek aleison (a wine vessel), leibó (I pour, I drop)
Italic Latin libáre (to pour, to libate)
Celtic Common Celtic *leja- (to flow), > 
Welsh lliant (a stream, a sea), llifo (to flow), Old Irish lie (a flood), Breton livad (inundation), Gaelic lighe (a flood, overflow)
Indic Sanskrit riyati (to let run)
Anatolian Common Anatolian *lohai- (to pour); >
Hittite lilái- (to let go)
Albanian lise", lyse" (a stream)
Germanic Germanic *lei-; > 
Gothic leithu (accusative; fruit wine)
Baltic Common Baltic *lí- (to pour); >
Lithuanian lieti (to pour), lyja (it is raining), Latvian leju (to pour), Old Prussian pralieiton (spilled), isliuns (poured out), Sudovian leit (to pour)
Slavic Common Slavic *liti (to pour), *lïjo. (I pour); >
Ukrainian liti, llyu, Belorussian lits (to pour), Old Church Slavonic liti, lêju, Bulgarian leja (I pour), Serbo-Croatian & Slovene liti, lijem, Czech liti, leji, Slovak liat', lejem, Old Polish lic' (to pour), Polish lac', leje., Upper Sorbian liju (I pour), Lower Sorbian las' (to pour), Russian lit', lju
Notes: A typical thematic root the first meaning of which was for sure 'to pour', often in ritual, religious purposes (like English libation). It is interesting that some parallels can be seen in verbs like 'to pour' and 'to drink': PIE *lei- and *poi-, Latin libo and pibo (though the latter reflects the root reduplication), Slavic liti and piti, etc. This makes us think of a sort of verb type in Proto-Indo-European.