When speakers imitate a word form a foreign language and at least partly adapt in sound or grammar to their native speech ways, the process is known as borrowing, and the word thus borrowed is a loanword. Moreover, the history of a loanword may be quite complex because such words have often passed through a series of languages before reaching English. In addition, English language barrowed thousands of words from many languages such as; Arabic, Latin, Greek, French and Italian. According to one survey, the percentage of modern English words derived from each language group are as follows:
(including words used only in scientific / medical / legal contexts):

Latin ~29%
French: ~29%
Germanic: ~26%
Others: ~16%

Besides, There are numerous Arabic loanwords in English, i.e., words of English acquired directly from Arabic or indirectly, by passing from Arabic into a third language (often Spanish) and then into English.
Here in the following list there are some Arabic loanwords in English:

Admiral
أميرال بحار, amīr al-bihār commander of the seas.

Alchemy
الكيمياء alkīmiyā, from Greek khēmia, khēmeia, art of transmuting metals

Alcohol
الغول - الكحول

Algebra
الجبر al-jabr, the restoring of missing parts. The modern mathematical sense comes from the title of the book al-kitāb al-mukhtaṣar fī ḥisāb al-jabr wa-l-muqābala, "The Compendious Book on Calculation by Completion and Balancing" by the 9th-century mathematician Abu Ja"far Muḥammad ibn Mūsa al-Khwārizmī.

Algorithm and algorism
الخوارزمي al-khwārizmī, a short name for the mathematician Muhammad ibn Mūsa al-Khwārizmī. The appellation al-Khwārizmī means "from Khwārizm".

Amber
Amber/anbar

Artichoke
الخرشوف al-xurshūf

Checkmate
شاه مات shah māt, "The king is dead"

Coffee
قهوة qahwa,

Cotton
قُطْن qutun

Ghoul
غول ghūl

Giraffe
زرافة zarāfa

Jasmine, Jessamine
from Arabic ياسمين yas(a)min.

Jinn
Arabic is الجن al Jinn (note that genie is not derived from this, though it may be influenced by it)

Lemon
ليمون "citrus fruit,".

Orange
From Arabic word نارنج naranj, from Tamil via Sanskrit and Persian.

Saffron
زعفران saffron (or zaffarān), species of crocus plant bearing orange stigmas and purple flowers.

Sugar
سكّر sukkar, sugar.

Sumac
summāq "سمَاق", from Arabic.

Zero
صفر sifr, cipher, zero.

Rice
"riz", from Arabic رز.

References:

"List of Arabic loanwords in English". Wikipedia. 29 January 2010 at 09:25
< http://en.wikipedia.org/wiki/List_of_English_words_of_Arabic_origin >