a. 不断侵袭的

Besetting \Be*set"ting\, a.
Habitually attacking, harassing, or pressing upon or about;
as, a besetting sin.


Beset \Be*set"\, v. t. [imp. & p. p. {Beset}; p. pr. & vb. n.
{Besetting}.] [AS. besettan (akin to OHG. bisazjan, G.
besetzen, D. bezetten); pref. be- + settan to set. See
{Set}.]
1. To set or stud (anything) with ornaments or prominent
objects.

A robe of azure beset with drops of gold.
--Spectator.

The garden is so beset with all manner of sweet
shrubs that it perfumes the air. --Evelyn.

2. To hem in; to waylay; to surround; to besiege; to
blockade. ``Beset with foes.'' --Milton.

Let thy troops beset our gates. --Addison.

3. To set upon on all sides; to perplex; to harass; -- said
of dangers, obstacles, etc. ``Adam, sore beset, replied.''
--Milton. ``Beset with ills.'' --Addison. ``Incommodities
which beset old age.'' --Burke.

4. To occupy; to employ; to use up. [Obs.] --Chaucer.

Syn: To surround; inclose; environ; hem in; besiege;
encircle; encompass; embarrass; urge; press.