(chemistry) any group of elements whose chemical and physical properties have similarities, and that vary progressively through the series; evident within the periodic table

(physics) Any of several series of spectral lines of hydrogen that correspond to quantum transitions between the various allowed energy levels of the hydrogen atom.

(archaic or literary, poetic) Without moisture; dry. / (archaic or literary, poetic) Of thoughts, etc.: barren, fruitless. / (obsolete) Of fabrics: threadbare, worn out.

(ecology) A natural succession of animal or plant communities in an ecosystem, especially a series of communities succeeding one another from the time a habitat is unoccupied to the point when a climax community is achieved.

(obsolete) A claw, a talon.

(obsolete or Britain, dialectal) Individual, separate, set apart. / (obsolete or Britain, dialectal) Different; diverse.

(agriculture) The rearing of silkworms for the production of silk.

One after another, in order; taking one topic or subject at a time in an order; sequentially.

(chiefly law) Point by point; sequential.

(textiles) A type of worsted cloth. / (by metonymy) A garment made of this fabric.