I read a Hadīth which mentions that a house, horse and a woman are three things that could either prove good or bring bad luck for a man. Could you explain the meaning of this please? How can we label anything as a symbol of bad luck?

In order to understand a single Hadīth, it is imperative to study all the Ahādīth of similar texts. The Hadīth you have mentioned has come in most of the major books of Hadīth in the words near to the ones you have quoted. However, the following text of it contained in the sixth volume of Imam Ahmad Ibn Hambal’s Musnad presents the true picture in this regard:

Abū Hassān reports that two people came to A’ishah and said to her that Abū Hurayrah narrates that the Prophet used to say that bad luck is to be found only in women, horses and houses. At this A’ishah replied: By the God who revealed the Qur’ān to the Prophet! the Prophet never said this; what he did say was that the People of the Jāhilliyyah hold this opinion ...

It is evident from this text of the Hadīth that this saying has been erroneously attributed to the Prophet (sws). He had actually quoted the views held by the people of Jāhilliyyah (the age of ignorance).