To find an english word, use the Search by English text box. If you wish to find part of a word use the adjacent drop down list. For example a search on "car" by starts with could match care, by contains could match scary, by ends with could match scar.
The Search by Japanese text box allows searching by any of the Japanese alphabets (Romaji, Hirgana, Katakana or Kanji).
The search will also find de-conjugated matches of the root word.
For example: "tabeta" (the past tense of 'to eat') will match on taberu (the verb 'to eat')