All 3 Uses of

relative
in
Of Human Bondage

I suppose you'll communicate with the relatives.'†
Chpt 85-86 *

relatives = people related by blood or marriage

In these matters a periphrase was demanded by the decorum of life, but, as he asked another question instead, it flashed through him that the doctor must be accustomed to the impatience of a sick man's relatives.†
Chpt 107-108

The Frenchman left them for friends at another table, and Cronshaw, with the lazy enunciation which was one of his peculiarities, began to discourse on the relative merits of Kent and Lancashire.†
Chpt 41-42 *

Definitions:

(1) (relative as in: the relative importance)
compared with something else (not an absolute value or not complete)
(2) (relative as in: they are relatives)
connected
in various senses, including:
- a person related by blood or marriage -- as in "The hospital won't let me visit her because I'm not a relative."
- a plant or animal related by origin or grouping -- "The closest relative of the dog is the gray wolf."
(3) (relative as in: questions relative to the topic)
related to
(4) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

More specialized and less common senses of the word are found in philosophy, grammar, and music. Consult a comprehensive dictionary if you wish to see those. All senses have to do with relationships.