treeWordAlphavitDB.js

var dictinary = {};

function addWord(word, value) {
  value = value ? value : word
  var letters = word.split('')
  var newDic = letters.reduce((prev, curr, i) => {
    if (letters.length -1 === i) {
      return prev[curr] = value
    }
    return prev[curr] ? prev[curr] : prev[curr] = {}
  }, dictinary)
}

function getWord(val) {
  var key = val.split('')
  var step = dictinary
  for (let i=0; i<key.length; i++) {
    try { step = step[key[i]] }
    catch(err){ return false }
  }
  return step ? step : false
}

var words = [
'ФАВНА', 'ФАВОРИТ', 'ФАЗ',
'ФАЗАН', 'ФАЗИС', 'ФАКЕЛ',
'ФАКИР', 'ФАКСИМИЛЕ', 'ФАЛ',
'ФАЛАЛЕЙ', 'ФАЛАНГА', 'ФАЛДА']

words.forEach(word => addWord(word))

console.log('getWord', getWord('ФАКЕЛ'))
console.log('getWord', getWord('ФАКЕЛs'))