The word "offsetted" is not actually a legitimate word recognized by many dictionaries. Instead, the standard past tense of "offset" is simply "offset." Some synonyms for "offset" include counterbalance, compensate, balance, counteract, and set off. These words are used to describe the act of balancing or counteracting the effects of something else. For example, you might offset the cost of buying an expensive gadget by selling some of your other possessions. Or a company might choose to offset their carbon emissions by investing in renewable energy projects. In any case, using precise language helps to communicate your ideas with clarity and accuracy.