Meanings of Sayyid and Master
The Prophet called himself the Sayyid of all human beings. In addition he called his grandson al-Hasan a Sayyid in absolute terms. (Inna waladi hadha sayyidun). He also ordered the Ansar, when he saw Sa`d ibn Mu`adh coming, as related by Bukhari in his Sahih: Qumu li sayyidikum or "Stand up for your master."
The implications of that term on the basis of these narrations are that it entails leadership, rank, and respect.
The word "master" is used both in the lofty senses mentioned above, as well as in the possibly lowly senses of "sahib" [owner], as in "sahib al-bayt", "sahib al-kalb," the owner of the house, of the dog etc.
There are further lexical senses which taint the word "master," such as the Western conception of the word in the context of slavery. An American ear may hear connotations of transatlantic slavery etc. in the words "slave" and "master" whereas such connotations of abuse and injustice are absent from `abd, mamluk, and sahib, not to say sayyid.
That is partly why the Christians have "lord" instead of "master" in a similar context, but they also use it for "THE Lord," and so when it comes to Prophets the doctrinal aberration of ascribing divine lordship becomes too glaring, and so Muslims prefer to use "Master," although some resourceful translators came up with "liege-lord," but "master" is still the better rendition. Allah knows best.