Fria wrote:I was told that
sparen means both,
to scare and
to spare, but so far no proof for that in dictionaries
Can you tell me? Dank je wel!
Told by an untrustworthy source, apparently.

Or you misunderstood them.
"Sparen" does indeed mean
to spare in the meaning of "sparing someone's life". In phrases like "Spare me your excuses", you'll use "besparen" instead in Dutch. The other, more frequent, meaning is
to save (money).