कृ

डुकृञ् = ड उ क र ञ OR ड उ क ऋञ

1. verb(fear) verb(stone + shining/sharp) surface = may refer to oldowan or achulean stone making = do and hold stone shining surface (with fear/ beware)
   verb(fear) stone superior surface = make surface superior but be ware
   do(Curve) stone superior surface

2. verb(fear) verb(hand held + water) surface = may refer to pre-oldowan movement, where the natural fear of water was overcome

कृञ् = क र ञ or क ऋ ञ
shining/sharp stone surface = violence. c
Stone superior surface

कृ as संयुक्ताक्षर predates its usage inडुकृञ् where it is used as part of वर्ण समास /धातु
कृ = क ऋ
means hand/hold superior = prehensile side of hand.
Superior could have meant “upper” but use in inडुकृञ् indicates that ऋ meant functional superiority and not directional. प्लुत meaning speed also indicates non prehensile leg.
refer to क्ल प्ल कृ प्र also

रूढ अर्थ [कृ] (https://kosha.sanskrit.today/word/sa/kR?q=%E0%A4%95%E0%A5%83&scope=kosha)

1. Do = refers to stone tool making
2. Make = refers to stone tool making
3. of हिंसा = हिंसा

commentary
I do not know which meaning is correct, original meaning as on now.
But this धातु represents one of the most important junctures in the evolution of Homo from apes.
Interesting to observe that there is no डु in हिंसा.