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.
Description. With lengths up to 100 feet (30 m) and weights up to 150 tons (136 metric tons), the blue whale is the largest animal that ever lived on this planet. An average individual is 70 feet (21 m) long and weighs 100 tons (90 metric tons).