1.  crossing(n = noun.act) - traveling across;
Derived form verb cross₁

2.  crossing(n = noun.object) ford - a shallow area in a stream that can be forded;

3.  crossing(n = noun.location) - a point where two lines (paths or arcs etc.) intersect;
Derived form verb cross₂

4.  crossing(n = noun.artifact) carrefour, crossroad, crossway, intersection - a junction where one street or road crosses another;
Derived form verb cross₂

5.  crossing(n = noun.artifact) crossover, crosswalk - a path (often marked) where something (as a street or railroad) can be crossed to get from one side to the other;
Derived form verb cross₁

6.  crossing(n = noun.act) cross, crossbreeding, hybridisation, hybridization, hybridizing, interbreeding - (genetics) the act of mixing different species or varieties of animals or plants and thus to produce hybrids;
Derived form verb cross₈

7.  crossing(n = noun.act) - a voyage across a body of water (usually across the Atlantic Ocean);
Derived form verb cross₁

1.  The act by which anything is crossed; as, the crossing of the ocean. [1913 Webster]

2.  The act of making the sign of the cross. Bp. Hall. [1913 Webster]

3.  The act of interbreeding; a mixing of breeds. [1913 Webster]

4.  Intersection, as of two paths or roads. [1913 Webster]

5.  A place where anything (as a stream) is crossed; a paved walk across a street, or a set of marks across the street pavement indicating that this is a designated location for pedestrians to cross. [1913 Webster]

6.  Contradiction; thwarting; obstruction. [1913 Webster]

crossing, n.
1 a place where things (esp. roads) cross.
2 a place at which one may cross a street etc. (pedestrian crossing).
3 a journey across water (had a smooth crossing).
4 the intersection of a church nave and transepts.
5 Biol. mating.

Idiom:
crossing over Biol. an exchange of genes between homologous chromosomes (cf. RECOMBINATION).

N  crossing, intersection, interdigitation, decussation, transversion, convolution, level crossing, reticulation, network, inosculation, anastomosis, intertexture, mortise, net, plexus, web, mesh, twill, skein, sleeve, felt, lace, wicker, mat, matting, plait, trellis, wattle, lattice, grating, grille, gridiron, tracery, fretwork, filigree, reticle, tissue, netting, mokes, rivulation, cross, chain, wreath, braid, cat's cradle, knot, entangle, cloth, linen, muslin, cambric, crossing, crossed, matted, v, transverse, cross, cruciform, crucial, retiform, reticular, reticulated, areolar, cancellated, grated, barred, streaked, textile, crossbarred, cruciate, palmiped, secant, web-footed, cross, thwart, athwart, transversely, at grade, crosswise, crossing, intersection, interdigitation, decussation, transversion, convolution, level crossing, reticulation, network, inosculation, anastomosis, intertexture, mortise, net, plexus, web, mesh, twill, skein, sleeve, felt, lace, wicker, mat, matting, plait, trellis, wattle, lattice, grating, grille, gridiron, tracery, fretwork, filigree, reticle, tissue, netting, mokes, rivulation, cross, chain, wreath, braid, cat's cradle, knot, entangle, cloth, linen, muslin, cambric, crossing, crossed, matted, v, transverse, cross, cruciform, crucial, retiform, reticular, reticulated, areolar, cancellated, grated, barred, streaked, textile, crossbarred, cruciate, palmiped, secant, web-footed, cross, thwart, athwart, transversely, at grade, crosswise.