ukrstiti

1. (ukrstiti se) to cross; to intersect; to cross paths
   Naši putevi su se ponovo ukrstili posle deset godina. — Our paths crossed again ten years later.
   Ove dve ulice će se ukrstiti tek kod pijace. — These two streets will only cross at the market.
2. to cross
   Vitezovi su ukrstili mačeve. — The knights crossed swords.
   Na trenutak smo ukrstili poglede. — For a moment our eyes met.
3. (of plants, animals) to crossbreed; to hybridize
   Naučnici su ukrstili dve sorte pšenice. — Scientists crossbred two varieties of wheat.
4. (of data) to cross-check; to cross-reference
   Policija je ukrstila podatke i pronašla osumnjičenog. — The police cross-checked the data and found the suspect.

For folding arms or crossing legs, prekrstiti ruke/noge is usually used.