" extensively "

1: to a large extent or degree;

  * e.g., " ... several beaches were extensively damaged by the hurricane "

•  Synonyms : 

•  astronomically,

•  big-time,

•  broadly,

•  colossally,

•  considerably,

•  enormously,

•  greatly,

•  highly,

•  hugely,

•  largely,

•  massively,

•  monstrously,

•  monumentally,

•  much,

•  sizably,

•  staggeringly,

•  stupendously,

•  tremendously,

•  utterly,

•  vastly

•  Antonyms : 

•  little,

•  negligibly,

•  nominally,

•  slightly

1: having considerable extent;

  * e.g., " ... a rock hound whose extensive reading enables him to identify just about any rock or mineral "

•  Synonyms : 

•  broad,

•  deep,

•  expansive,

•  extended,

•  far-flung,

•  far-reaching,

•  rangy,

•  sweeping,

•  wide,

•  wide-ranging,

•  widespread

•  Antonyms : 

•  narrow