'Companion' in the Bible

while Paul deemed it undesirable to have as their companion one who had deserted them in Pamphylia and had not gone on with them to the work.

But Paul chose Silas as his travelling companion; and set out, after being commended by the brethren to the grace of the Lord;

But although my companion Titus was a Greek they did not insist upon even his being circumcised.