Where does “bombesikker” come from?

bombesikker (Danish) comes from Danish sikker, from Middle Low German seker, from Old Saxon sikur, from Proto-West Germanic sikur, from Latin sēcūrus, from Latin sē-, from Latin sex, from Proto-Italic seks — six.

bombesikker (Danish): bombproof

Definitions

bombproof

Ancestry of “bombesikker”, step by step

bombesikker traces back through two separate lines of ancestry.

via Danish sikker

Step	Language	Word	Meaning
1	Danish	sikker	safe, secure; sure, certain
2	Middle Low German	seker	—
3	Old Saxon	sikur	—
4	Proto-West Germanic	sikur	secure, safe; sure, certain
5	Latin	sēcūrus	careless, negligent
6	Latin	sē-	apart-; aside-; away
7	Latin	sex	six; 6
8	Proto-Italic	seks	six
9	Proto-Indo-European	swéḱs	six

via Danish bombe

Step	Language	Word	Meaning
1	Danish	bombe	bomb; to bomb
2	French	bombé	rounded, convex; past participle of bomber
3	Italian	bomba	bomb
4	Italian	bombo	bumblebee; buzzing
5	Latin	bombus	A buzz or humming sound
6	Ancient Greek	βόμβος	any deep, hollow sound, humming, buzzing,...

Every word from Proto-Indo-European swéḱs →Every word from Latin sē- →Every word from Proto-Italic seks →