¹ start verb

• to do the first part of something : to begin doing something
• to begin to work on, produce, or give attention to (something)
• to cause (something) to begin : to cause (something) to begin in a specified way

² start noun

• the time at which something begins—usually singular —often + of
• the first part of an activity, development, event, etc.—usually singular —often + of
• the first opportunity to begin a career—usually singular —often + in