lower1. 1  to cause to descend; let or put down: to lower a flag. 2  to make lower in height or level: to lower the water in a canal. 3  to reduce in amount, price, degree, force, etc. 4  to make less loud: Please lower your voice.
Biggest Whale-Basilosaurus (60 Tons). Basilosaurus (Nobu Tamura). Unlike the other mammals on this list, Basilosaurus can't lay claim to being the largest-ever of its breed--that honor belongs to the still-extant Blue Whale, which can grow to as much as 200 tons.
A member of the order Cetacea, the blue whale (Balaenoptera musculus), is thought to be the largest animal ever to have lived. The maximum recorded weight was 190 tonnes for a specimen measuring 30 metres (98 ft), whereas longer ones, up to 33.4 metres (110 ft), have been recorded but not weighed.