Decliners are fastidious folk, they won't touch a door knob without sanitising it, let alone shake hands.
后退式的人比较挑剔，如果门把手不消毒都不会碰，更不要说握手。
英语百科
Decline
Decline involves change over time, for example:
Note: distinguish the noun decline from the adjective obsolete. Decline refers to the degenerating of something (compare obsolescence) whereas obsolete refers to the outdatedness of something or labels something as no longer in use. Decline represents the process of declining, a gradual sinking and wasting away.