Proto-Indo-European Roots

Root/Stem: *bal-
Meaning:  strength
Hellenic Greek beltión 'better'
Italic Latin de-bilis 'weak'
Celtic Common Celtic *bal- 'strong' >
Old Irish odbal 'strong', Middle Irish balc 'strong', Irish dibeal 'old', Welsh balch 'proud', Breton balc'h
Indic Sanskrit bala- 'strength', baliyán 'stronger'
Balkan Phrygian balaios 'big, fast'
Germanic Common Germanic *pala- 'strong, solid' >
Middle Dutch & Low German & Frisian pal 'strong, firm'
Slavic Common Slavic *boljï, *bolje 'more, bigger' >
Russian bolee 'more', bol'shoj 'big'
Notes: A rather unique word, for the phoneme *b is found very rarely in pure Indo-European words. The glottalic theory suggested that it never existed at all. In any case, this root is maybe the most reliable proof of the existance of *b in Proto-Indo-European. Otherwise, it was an early borrowing from some outside language.