“Allah Akbar” means Allah is the greatest (a more literal translation is; Allah is greater). Akbar (اكبر) refers to greatest. In Hebrew the word for mouse is Achbar (עַכְבָּר).
In the Hebrew word for “mouse” (achbar עַכְבָּר), the kaf כ (the second letter, reading from right to left) omits the dagesh (the dot in the middle of the letter ) therefore the pronunciation of achbar is not with a “k” sound but with a “ch” sound (“ch” as in the Scottish “loch” or the German “achtung”). Thus, anybody who is familiar with the pronunciation of both languages will know AllahuAkbar does NOT mean Allah is a mouse in Hebrew. They are pronounced noticeably dissimilar to each other.
In fact, the key Hebrew letter (Kaf כ) would not even sound like ﻚ in Arabic, it would sound like ﺥ
To illustrate this further I have presented the audio for the Arabic word Akbar (اكبر) and the Hebrew word for mouse (Achbar – עַכְבָּר) – you will clearly hear the two are not the same.
Christian missionaries, try not to look silly…
Please stop peddling this outrage – it is false and immature. I have already caught TWO Christians peddling this lie. One of these miscreants claimed he had consulted a “professor” at the Moody Bible Institute – I have corrected him via YouTube email and he has graciously accepted the correction.
Would the Christians like it if Muslims began sifting through Biblical Greek and Hebrew words and comparing them with like-sounding words from other languages? No. It is immature and futile the meaning in the intended language is what matters.
Ignorant Christians insult Arab Christians
These Christians are also insulting Arab Christians (i.e. the Copts) who also use the word Akbar (اكبر). Some evangelical folk just do not think before speaking. Grow up, the lot of you!
 There are three letters in Hebrew, Bet ב, Kaf כ, and Peh פ, which change in pronunciation depending on the presence/absence of a dot called the degesh.
For the Kaf כ, if the dagesh is not present then the pronunciation would be similar to ﺥ (Ch as in lochness or the German “Achtung). If the dagesh is present then the pronunciation is similar to the English k and the Arabic ﻚ
: In the word for mouse (עַכְבָּר), the dagesh is missing from the Kaf כ so the pronunciation is NOT similar to the English “K” but is similar to the Arabic ﺥ (i.e. ch in loch).
 I have appended a story from an Israeli blog of a Hebrew learner making the same mistake (confusing achbar (עַכְבָּר) with akbar (اكبر). The Israeli blog confirm the two words are not phonetically the same either. However, it is a mistake untrained ears could innocently fall into. See the comment section; as the story is rather lengthy it shall not be included in the main body of the text.