Ayah means evidence.
 (There are 114 chapters in the Quran, however there are only 112 unnumbered Bismillah's because Surah At-Tawbah does not have one at the beginning and even though the one at the beginning of Surah Al-Fatiha is its first verse hence part of it), there is another Bismillah in the middle of ayah 30 of Surah An-Naml 
 The "signs" refer to various phenomena, ranging from the universe, its creation, the alternation between day and night, rainfall, and the life and growth of plants

