Another word for widening

In investigating the effects of mixture on the widening of lines in absorption spectrum, R.

The harbour, originally constructed as a refuge for British ships of war, is one of the best on the east coast, and has been improved by the widening of the piers and the extension of the breakwaters.

And, on the whole, the widening of intellectual interests is the chief feature by which the second period of Scholasticism may be distinguished from the first.

The angel ignored her and dropped beside her, wringing his hands helplessly.  The blond woman dangled over the widening chasm, clutching Katie's hand.  She braced her feet against the side of the chasm and walked upward, until Toby could grab her belt.  The angel pulled hard, and Katie pushed Deidre on top of the angel, who yelped.

The leaves are frequently irregular in outline, the lobes rather short and blunt, widening towards the end, but with setaceous points; the acorns are nearly globular.