Example: "He worked for a brokerage house"
Example: "We firmly believed it"
Example: "Firm convictions"
Example: "A firm contract"
Example: "His voice was firm and confident"
Example: "Stocks are still firm"
Example: "Holds a firm position as the country's leading poet"
Example: "Firm muscles"
Example: "The post was still firm after being hit by the car"
Example: "A firm ally"
Steadfast, secure, solid (in position)
Example: "It's good to have a firm grip when shaking hands."
Fixed (in opinion)
Example: "He was firm that selling his company would a good choice and didn't let anyone talk him out of it."
Durable, rigid (material state)
Example: "Firm flesh; firm muscles, firm wood; firm land (i.e. not soft and marshy)"