Today's Date in the Shire
0 2 Lithe
Fun and Games
Walk to Rivendell
Malbeth the Seer
Dutch belegeren, from be- (akin to Old English be-) + leger camp; akin to Old High German legar bed
1 : to surround with an army so as to prevent escape : besiege, beset
2 : to hem in : bottle up
3 : to subject to oppressive or grievous forces : harass
"Mundburg the mighty under Mindolluin, / Sea-kings' city in the South-kingdom / foe-beleaguered, fire-encircled" is what the Lay of the Mounds of Mundburg tells us.
The last of these staves also serves as a poetic definition of the word itself. Throughout the Lord of the Rings, the word is practically solely used in that context of Minas Tirith the beleaguered city in book five.
In the Silmarillion, there are more sieges in which it is used: Círdan at the Belfalas, Angband and Gondolin are all at one time or another 'beleaguered'. All in all, Tolkien obviously likes beleaguered as a Germanic synonym for 'under siege' and others; the transitive verb itself is rarely, if at all, used.
(Etymology and definition taken from www.m-w.com)