def has_prefix(sub_s, dictionary):
	"""
	:param sub_s: (str) A substring that is constructed by neighboring letters on a 4x4 square grid
	:param dictionary (list)
	:return: (bool) If there is any words with prefix stored in sub_s
	"""
	prefix_in_word = False
	for word in dictionary:
		if word.startswith(sub_s) is True:
			prefix_in_word = True
			break
	return prefix_in_word